The present invention relates to the configuration of a winding device in an automatic winder, a double twister, a false twister, or the like and the configuration of a traverse drum for use in the winding device, and in particular, to a technique for preventing ribbon winding during production of winding packages to improve yarn quality.
In conventional textile machines, automatic winders are well known which comprise a traverse drum having a traverse groove formed in its peripheral surface and through which a yarn unwound from a spinning bobbin or the like is traversed to produce a winding package rotationally driven by the traverse drum in contact therewith. Double twisters and false twisters are also known which comprise a traverse drum having a traverse groove formed therein to traverse a yarn.
In addition, since the yarn traversed through the traverse groove is sequentially wound around the winding package, its package diameter increases gradually. When the package diameter and the diameter of the traverse drum have a certain relationship, the ribbon winding occurs on the winding package. The ribbon winding is a phenomenon in which the yarn wound on the winding package passes through substantially the same yarn path during a certain period, so that an extremely small number of intersections of the yarn are formed on the package. A winding package in which the ribbon winding has occurred may cause sluffing or yarn breakage by entanglement of yarn (a process called xe2x80x9clatchingxe2x80x9d) during a postprocess when the yarn is unwound. Many methods for preventing ribbon winding on the winding package have been provided, including periodic braking of the drum or the package.
Although the above described ribbon winding preventing methods according to the prior art have substantially solved the ribbon winding problem in terms of the appearance of the package, there is still a large difference between ribboned layers and the other layers in, for example, winding performance for fast unwinding during the postprocess.
A method is thus well known which forms a shortened passage in part of the traverse groove formed in the traverse drum to change the winding value (number of winding) in order to enable two winding values for the traverse drum to be switched. This conventional configuration, however, requires the two winding values to be switched during a winding operation of an automatic winder or the like. For example, in a traverse drum with 2 winding values (2W) and 3 winding values (3W), the winding values is alternately changed for each traverse operation. Accordingly, complicated control is required and the yarn path must frequently be changed. Therefore, this method is not efficient.
The problems to be solved by the present invention have been described, and means for solving these problems will be explained below.
In the present invention for using a traverse groove formed in a traverse drum to traverse and wind a yarn into a package, the traverse drum has a plurality of continuous traverse grooves for different winding values formed therein.
The present invention has means for switching a yarn path to determine which of the plurality of continuous traverse grooves for different winding values is used to traverse the yarn.
In the present invention for using a traverse groove formed in a traverse drum to traverse and wind a yarn into a package, means for detecting a diameter of the package at which the ribbon winding occurs is provided to provide such control that the winding value for the traverse drum is changed near a diameter at which ribbon winding has occurred.
In the present invention, the traverse drum has a plurality of continuous traverse grooves formed therein and having different winding values.
In the present invention, the plurality of continuous traverse grooves are formed substantially completely independently.
In the present invention, a continuous traverse groove for 2 winding values and a continuous traverse groove for 2.5 winding values are formed.
In the present invention, a half or more of the plurality of continuous traverse grooves are independently formed and the remaining traverse grooves constitute a common passage.
In the present invention, a forward and backward portions of at least one continuous traverse groove have different winding values.